Source

Department of Prosthodontics and Periodontics, Dental School of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil. daiaperuzzo@yahoo.com.br

Abstract

The purpose of the present investigation was to evaluate the effects of sodium lauryl sulphate (SLS), present in a commercial dentifrice toothpaste, on the formation of volatile sulphur compounds (VSC) and tongue coating in a panel of periodontally healthy subjects. A two-step blinded, crossover, randomized study was carried out in 25 dental students with healthy periodontium; these were divided into two experimental groups: SLS (toothpaste with SLS) and WSLS (toothpaste without SLS). The volunteers received the designated toothpaste and a new toothbrush for a 3x/day brushing regimen for 2 periods of 30 days. A seven-day washout interval was used between the periods. The assessed parameters were: plaque index (PI), gingival index (GI), organoleptic breath (ORG), VSC levels by portable sulphide monitor before (H1) and after (H2) cleaning of the tongue, tongue coating wet weight (TC) and benzoyl-DL-arginine-naphthylamide (BANA) test from tongue coating samples. The intra-group analysis showed a decrease in the median of organoleptic scores from 3 to 2 after 30 days for the SLS group (p < 0.05). The inter-group analysis showed lower values in ORG and H1 for the SLS group (p < 0.05). There was no difference between the amount of TC in SLS and WSLS groups. In the BANA test, the presence of SLS did not affect the BANA number of +/- results (p > 0.05). These findings suggest that sodium lauryl sulphate (SLS), present in toothpaste, appears to prevent VSC formation in morning bad breath regardless of the amount of tongue coating in periodontally healthy subjects.

Source

Abstract

BACKGROUND:

Chlorhexidine (CHX) and sodium lauryl sulphate (SLS), the most widely used detergent in dentifrice (toothpaste), may counteract. Consequently, studies about this interaction suggested that care is required when combining both these compounds, even when they are introduced separately into the oral cavity. The purpose of the present study was to investigate the effect of toothbrushing with a SLS-containing toothpaste in one jaw, on the plaque inhibition of a CHX mouthrinse in the opposite jaw during a 4-day study period.

METHODS:

The study was an examiner-blind, randomised two-cell, crossover design. It used a 4-day plaque accumulation model to compare two different oral hygiene regimens with a washout period of 17 days. Sixteen healthy volunteers were enrolled in the study and received a thorough dental prophylaxis at the beginning of each 4-day test period. One jaw (upper or lower) was randomly assigned as the "study" jaw. The opposite jaw was assigned as the "toothpaste" jaw and served only to introduce the effect of brushing with a toothpaste in the study model. Two oral hygiene regimens were evaluated. During one randomly assigned test period, the "dentifrice" jaw was treated by toothbrushing with a 1.5% SLS-containing toothpaste and rinsed together with the "study" jaw with 0.2% CHX, thus forming regimen 1. As a control during the other test period, both the "toothpaste" jaw and "study" jaw were only rinsed with 0.2% CHX, forming regimen 2. No other oral hygiene methods were allowed. After 4 days of undisturbed plaque accumulation, the amount of plaque was evaluated (Silness & Löe 1964). The "study" jaw was used to study the effect of the two regimens on the level of plaque accumulation at the end of the 4-day period.

RESULTS:

The overall plaque index was 0.36 for regimen 1 and 0.34 for regimen 2. There was no significant difference in plaque accumulation between the two regimens.

CONCLUSIONS:

Within the limitations of the present study design, it can be concluded that ordinary brushing with a 1.5% SLS-containing toothpaste (Colgate Bi-Fluor), followed by rinsing with water does not appear to reduce the level of plaque inhibition offered by a post-brushing CHX rinse.

Source

Institute of Dentistry, University of Turku, Finland. irma.rantanen@utu.fi

Abstract

Our aim was to study the effects of mildly flavoured sodium lauryl sulphate (SLS)-containing and detergent-free toothpastes with and without betaine (BET) on subjective symptoms of dry mouth in a randomised clinical trial. BET is an osmoprotectant that reacts with molecules to supply the surface with a water coating that protects cells from surfactants. Twenty-seven xerostomic patients and 18 healthy controls took part in the randomised, double-blind clinical trial with a crossover design. Three mildly flavoured toothpastes: (1) 4% BET, (2) 1% SLS and 4% BET, and (3) 1% SLS were used for six weeks each. The reference or washout paste contained neither SLS nor BET. The subjects' dental appointments were at the beginning of the trial and before and after the use of each toothpaste. At each appointment, the subjects were interviewed about subjective sensations of dry mouth (Visual Assessment Scoring (VAS) Index). The subjects did not report any adverse effects in connection with the use of the toothpastes. The VAS scores for lip dryness and eating difficulties were significantly lower for the BET paste (lip dryness: BET<BET+SLS; p < 0.005 and eating difficulties: BET<BET+SLS; p = 0.02; BET<reference; p = 0.003). The BET paste relieved dry mouth symptoms in 44% of the xerostomic patients, the corresponding figures for the other pastes being BET+SLS 22% (p = 0.002 as compared with BET), SLS 18% (p = 0.022), and reference 7% (p = 0.000). In conclusion, all the mildly flavoured toothpastes used in this study were well accepted by the xerostomic subjects. Thus, other toothpaste components may be more mucosa-irritating than just SLS, or else they enhance the effect of SLS. The detergent-free, BET-containing toothpaste appeared to be associated with relief of some symptoms of dry mouth.

Source

Institute of Dentistry, University of Turku, Finnfeeds Finland, Espoo, Finland.

Abstract

The aim was to compare the effects of two sodium lauryl sulphate (SLS)-containing toothpaste formulations with and without betaine on human oral mucosa in vivo. The results are compared with the effect of a dry mouth toothpaste without SLS. Twenty subjects participated in the double blind, crossover study. The toothpastes with 1.2% SLS, 1.2% SLS and 4% betaine and with 4% betaine but not with SLS were placed on buccal mucosa in a test chamber and kept in place for 15 min. The condition of the mucosa was studied both visually and using electrical impedance (EI) for up to 45 min. Both SLS-containing pastes had a similar, irritating effect on the mucosa as judged both by the appearance of the mucosa and the EI measurements. The dry mouth toothpaste (with betaine only) showed no significant irritation of the mucosa. Betaine did not reduce the mucosa-irritating effect of the SLS-containing toothpaste formulation. The surfactant-free toothpaste did thus not irritate the human oral mucosa in vivo while the SLS-containing pastes did.

Source

Abstract

Sodium lauryl sulfate (SLS), the most widely used detergent in toothpastes, has been reported to cause adverse effects on oral soft tissues. This double-blind cross-over study describes the oral mucosal effects of SLS-containing toothpastes and pastes containing a zwitterionic detergent, cocoamidopropyl-betaine (CAPB) in an experimental model in 28 healthy females. Seven toothpastes, differing only in detergent concentration and/or type, were used: SLS (0.5, 1.0, 1.5%), CAPB (0.64, 1.27, 1.90%) and a placebo. Each participant applied 1 cm of assigned test toothpaste via a cap splint to the teeth and the mucosa of the upper jaw. The splints were used twice daily for 2 min during a period of 4 d, after which the participants were examined for oral desquamation. No other oral hygiene was allowed during the test periods. Ten days brushing with a detergent-free toothpaste was performed between each test period. Forty-five desquamative reactions were observed in 21 of 27 subjects (one was excluded) during the trial. Forty-two reactions were recorded during the SLS periods and the remaining three during the CAPB periods. The detergent-free toothpaste did not result in oral desquamation. SLS in toothpastes significantly increased the incidence of desquamation of the oral mucosa compared with toothpastes containing the detergent CAPB. The model used is not directly relevant to normal toothbrushing with toothpaste, but indicates that sensitive patients may contract mucosal irritation through SLS in toothpastes. Less toxic detergents, e.g. CAPB, are desirable in oral hygiene products.

Abstract

Sodium lauryl sulfate is one of the most widely used synthetic detergents in toothpaste. Generally, surface active agents lower the surface tension, penetrate and loosen surface deposits and emulsify or suspend the debris which the dentifrice removes from the tooth. The concentration in dentifrices usually ranges from 0.5-2.0%. It has previously been shown that sodium lauryl sulfate has the potential to initiate hypersensitivity to metal ions. Furthermore, the mucosal permeability will be increased to oil and water soluble compounds. Experiments from this laboratory indicate that sodium lauryl sulfate will interact with the deposition of fluoride on dental enamel. It is furthermore suggested that this interaction may have the potential to decrease the cariostatic effect of fluorides. Clinical studies from Denmark give support to this statement. In conclusion, sodium lauryl sulfate has some side effects, and future work should therefore be concentrated on finding other possible toothpaste detergents without these side effects.

Source

Department of Oral Pathology and Oral Medicine, St Bartholomew's and the Royal London School of Medicine and Dentistry, Whitechapel, London E1 2AD, UK.

Abstract

OBJECTIVE:

Sodium lauryl sulphate (SLS), an important component in many oral health products, is well established as a contact irritant in skin. Recent studies have suggested that it may also affect the structural integrity of oral mucosa. SLS is rarely used alone in dentifrices or mouthwashes and the aim of this study was to establish the effect of SLS both alone and in combination with Triclosan (TCN) and zinc (Zn) on the permeability barrier properties of normal human oral mucosa.

METHOD:

Ventral tongue mucosa was obtained from nine males and seven females within 60 h of death and stored frozen at -70 degrees C until use. The permeability of the tissue to tritiated water was measured after pretreatment for 15 min with SLS alone, SLS/TCN, SLS/Zn and a SLS/TCN/Zn mixture. Treatment with distilled water (DW) served as control. The histological appearance of the tissue before and after treatment was also examined by light microscopy.

RESULTS:

SLS treatment caused a significant increase in water permeability compared to control tissue (Kp = 11.7 +/- 1.00; 4.96 +/- 0.50 respectively; P < 0.005). Treatment with a SLS/TCN/Zn mixture, however, had no effect on the permeability to water (Kp = 5.5 +/- 0.56). Histological examination revealed that tissue exposed to SLS had a marked disruption of the epithelial surface whilst tissue treated with a SLS/TCN/Zn mixture was indistinguishable from controls.

CONCLUSION:

Although mucosa exposed to SLS alone showed an increase in permeability to water, the addition of TCN and Zn to SLS appeared to prevent this effect. As SLS is included in some dental products to solubilise compounds such as TCN, its presence may have no effect on the permeability barrier property of oral mucosa.

Source

Abstract

Triclosan and sodium lauryl sulfate (SLS) are antimicrobial agents used, both singularly and in combination, in dentifrices (toothpastes) and mouth-rinses. Studies by Waaler et al. (Scand. J. Dent. Res. 101 (1993) 192-195) with human volunteers showed that the adverse side-effects induced by SLS in mouth-rinses, i.e. desquamation of oral epithelium and a burning sensation, were lessened by the addition of triclosan. However, Baert et al. (Int. J. Exp. Pathol. 77 (1996) 73-78) showed that triclosan did not protect the hamster cheek pouch mucosa from irritation caused by SLS. The studies presented herein further evaluated, using a cell culture system, the triclosan-SLS interaction. The in vitro cytotoxicities of triclosan and SLS, alone and in combination, were determined with human gingival S-G epithelial cells and GF fibroblasts. The 24-h midpoint (NR50) cytotoxicity values towards the S-G cells were 0.052 mM triclosan and 0.0075% SLS and for the GF fibroblasts the respective values were 0.095 mM triclosan and 0.0127% SLS. Both agents at their NR50 values induced vacuolization. Coexposures of triclosan and SLS were additive in their cytotoxicities towards the S-G epithelial cells and GF fibroblasts. Pretreatment with triclosan potentiated the toxicity of a subsequent exposure of SLS to the S-G cells; a similar pretreatment of the GF fibroblasts with triclosan had no effect on a subsequent challenge with SLS.

Source

Colgate-Palmolive Co., Technology Center, Piscataway, NJ 08855, USA.

Abstract

Sodium lauryl sulphate (SLS) is used in toothpaste and mouth rinses as an emulsifying and surface cleaning agent. SLS has been implicated in an increased incidence of oral irritation in subjects predisposed to recurrent aphthous stomatitis (RAU). Hence, the purpose of this study was to determine the levels of SLS found in the oral cavity following rinsing with an SLS containing mouth rinse and brushing with a SLS containing dentifrice. An analytical method to separate SLS from saliva and other complex systems was developed. The method used high performance liquid chromatography (HPLC) and detection performed using conductivity measurements. Standard curves with known concentrations showed a detection limit of less than 0.4 ug SLS/ml of fluid. 2 clinical studies were conducted to determine the amount of SLS retained in the mouth by a healthy population after rinsing or brushing with commercially available products. The results showed, after rinsing, that 96% of the available SLS from the rinse was recovered in the collected samples within 2 min. Similarly, after brushing, 86% of the SLS contained within the toothpaste was recovered from the collected samples within the first 10 min. These results showed that the amount of SLS retained in the oral cavity was minimal and the contact time between SLS and the oral cavity was very short. A 2nd study was conducted to measure the amount of SLS retained in the mouth by a population susceptible to RAU. After rinsing, 97% of the available SLS was recovered within the first 2 min. Following brushing, 89% of the SLS in the dentifrice was recovered within the first 10 min. These results were comparable to those determined by the study involving the healthy population.

Source

Department of Oral Surgery and Oral Medicine, Faculty of Dentistry, University of Oslo, Norway.

Abstract

Skin reactions to 4 toothpastes were tested in 19 healthy dental students in a double-blind study. The hypothesis was that common toothpaste brands with and without sodium lauryl sulfate (SLS) and triclosan and with different additives/emulgators differ in irritation potential. An occlusion test system on human skin was used. The toothpastes tested were A) Zendium (non-ionic detergent), B) Solidox F (SLS/polyethylene glycol), C) Colgate Total (triclosan/copolymer/SLS/propylene glycol), and D) Solidox G (triclosan/zinc citrate/SLS/polyethylene glycol). Toothpaste C was the greatest irritant, causing skin erythema in 16 of the 19 subjects, whereas toothpaste D gave no reactions. Toothpaste B provoked three reactions (two severe), whereas toothpaste A caused only one mild reaction. Although this study was carried out on skin and hence not directly applicable to the oral cavity, these and previous results may indicate that a toothpaste without propylene glycol and SLS may be preferred by susceptible persons.

Source

Department of Oral Biology, Faculty of Dentistry, University of Oslo, Norway. assev@ulrik.uio.no

Abstract

The hypothesis to be tested in this study was that toothpastes containing sodium lauryl sulfate (SLS) is unsuitable vehicles for xylitol. The bacteriostatic (and cariostatic) effect of xylitol is assumed to be caused by intracellular accumulation of xylitol-5-P in plaque bacteria. Experiments were designed to investigate whether presence of SLS would affect the uptake of xylitol by interacting with the bacterial membranes and thus inhibit xylitol-5-P formation. It was shown in an in vitro study that even very low concentrations of the strong anionic detergent SLS inhibited uptake of xylitol and xylitol-5-phosphate formation by dental plaque totally. The mild nonionic detergent ethoxylated stearyl alcohol (30x EO) had no such effect. In vivo experiments with toothpastes containing xylitol and either the strong or the mild detergent, showed that xylitol in toothpaste with SLS was not available for the plaque bacteria and gave no adaptation to xylitol, whereas in the presence of 30x EO it was available, and a xylitol adaptation was observed. Glucose metabolism, which was also studied for the plaque samples, was not significantly affected by presence of any of the 2 detergents, indicating that the amounts of xylitol in toothpastes were presumably too low to give clinical significant effects, even when mild detergents are used.

Source

Department of Oral Surgery and Oral Medicine, Dental Faculty, University of Oslo, Norway.

Abstract

Sodium lauryl sulfate (SLS) is the most commonly used detergent in dentifrices. The present study was concerned with the effect of SLS content of toothpastes on oral epithelial desquamation in an experimental model. Ten dental hygiene students participated in this double-blind cross-over study. Five dentifrices with different concentrations of SLS (ranging from 0.0% to 1.5%) were used in randomized order in the study. One centimeter of each test dentifrice was applied in a cap-splint, which covered both attached and non-attached oral mucosa of the upper jaw for 2 min twice daily. The test period for each experimental dentifrice was 4 days, followed by a 10-day rest period. The dentifrice without SLS did not result in any onward reaction, whereas the dentifrice containing 1.5% SLS provoked desquamation in 60% of the subjects.

Source

Department of Periodontology, University of Wales College of Medicine, Cardiff, UK.

Abstract

The antibacterial activity of 4 triclosan-containing toothpastes was compared to a conventional fluoride dentifrice (toothpaste) and triclosan and sodium lauryl sulphate (SLS), both singly and in combination. A panel of 17 bacteria was tested by an agar dilution method. At concentrations typical of those found in toothpastes, triclosan and SLS displayed approximately equal antibacterial activity. A paste containing triclosan and zinc citrate appeared more active than the other triclosan toothpastes which, in general, showed marginal superiority over the conventional toothpaste. SLS, although included in dentifrice formulations for its detergent properties, may significantly contribute to the antibacterial profile of a product. The need for appropriate controls when evaluating experimental toothpastes is emphasized.

Source

Department of Periodontology, School of Dentistry, University of Ghent, Belgium.

Abstract

Dentifrices (toothpastes), two containing sodium lauryl sulphate (SLS) and one containing stearylethoxylate as surfactant, were gently rubbed on the mucosal surface of the medial wall of cheek pouches in adult male Syrian golden hamsters. Four daily applications were performed. On the fifth day, the animals were sacrificed and cheek pouch mucosal tissue was routinely processed for light microscopy. After applications of SLS containing toothpaste, the epithelium showed consistently prominent structural changes, especially hyperkeratinization, including ortho and para-keratinization, acanthosis with widening of the intercellular spaces, and varying degrees of basal hyperplasia. Identical morphological changes were also observed after application of a toothpaste containing only SLS as an agent. In contrast, after application of the stearylethoxylate containing toothpaste, as well as a toothpaste containing only stearylethoxylate as an agent, the epithelium remained essentially identical to the epithelium of cheek pouches treated with sterile saline, and to the nontreated cheek pouches. From these results, we may conclude that SLS is the agent responsible for the striking changes in the epithelial structure. The specific cytological effects of SLS on the epithelial cells remain to be further studied. Interestingly, application of SLS provides a useful system for the rapid production of acanthosis and hyperkeratinization in the stratified squamous epithelium of the hamster cheek pouch.